Key to males of the subgenus Parancistrum, based on gonopod structure

1 Anterior process (ap) serrated.......................................................................... 2

- Anterior process (ap) smooth........................................................................... 3

2 Posterior process (pp) very wide and considerably exceeding solenomere (s) (Figs 37, 39).................. M. turcicum

- Posterior process (pp) narrow and slightly shorter than solenomere (s) (Figs 19, 21)...................... M. serratum

3 Promere with a more or less incised apical margin.......................................................... 4

- Promere gradually convex apically...................................................................... 5

4 Promere’s apical margin shallowly incised (Figs 48–50), anterior solenomere protrusion (asp) more slender, tapering, turned posteriad (Figs 48, 51–54)............................................................... M. arcuatum sp. n.

- Promere’s apical margin deeply incised (Figs 28–29), anterior solenomere protrusion (asp) shorter, blunter, pointing distad (Figs 28, 30)............................................................................. M. tenenbaumi

5 Posterior process (pp) subequal to solenomere(s); anterior solenomere protrusion (asp) smooth (Figs 4, 6–7)... M. curvifolii

- Posterior process (pp) shorter than solenomere (s); anterior solenomere protrusion (asp) with apical plumose outgrowths (Figs 14, 16)............................................................................... M. genezarethanum